Derivatives (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014 contracts	Jun. 30, 2013	Jun. 30, 2014 contracts	Dec. 31, 2013
Credit Derivatives [Line Items]
Counterparty default losses on forward contracts	$ 0
Commitments and contingent liabilities
Number of interest rate derivatives held	296		296
Termination value of derivatives in net liability position	21,600,000		21,600,000
CollateralPostingClearing	33,200,000		33,200,000	13,000,000
Decrease in settlement values of the Bank's derivative assets	(1,516,000)		(1,516,000)
Gain (loss) on nonhedge derivative instruments related to credit valuation adjustments	(1,800,000)	1,823,000	(3,000,000)
Interest Rate Forward Sales Commitments [Member]
Credit Derivatives [Line Items]
Commitments and contingent liabilities	482,000,000		482,000,000
Commitments To Originate Loans Held For Sale [Member]
Credit Derivatives [Line Items]
Commitments and contingent liabilities	323,047,000		323,047,000
Interest Rate Swap [Member]
Credit Derivatives [Line Items]
Notional amount of credit risk derivatives	$ 1,500,000,000		$ 1,500,000,000